Inkjet printing systems are being used for printing an expanding range of commercial printing applications. As the range of applications has expanded, a need has developed to extend the printable width of the inkjet printing systems. This need has typically been met by using larger arrays of inkjet printheads. When using a system with multiple printheads, however, it is important that colors printed by each of the printheads be consistent. EP 1 013 450 disclosed a system for supplying ink to multiple printheads from a single liquid supply system. By supplying all the printheads with ink from the same liquid reservoir, the liquid supply system ensured that all the printheads are printing with a common ink.
While the system of EP 1 013 450 is effective, at some point, when a threshold number of printheads is exceeded, the system becomes impractical due to the large flow rates of liquid being supplied to and returned from the large number of printheads. As such, there is an ongoing need to improve how printing liquid is supplied to a large number of printheads.